How do I add a folder to my iPhone or iPad dock?

I want to have more apps in my iPhone dock, can I use a folder there?

The dock at the bottom of your iPhone or iPad's Home Screen is where you keep (or should keep) apps that you use frequently, because the dock is always on your screen, regardless of which page of apps you've swiped left or right to. It only fits four apps and most of us use more than four apps on a regular basis, so fitting more on the dock would be useful. You can accomplish this to a degree by using a folder in your dock. It might not be worth it if you only have a couple Home Screens worth of apps to swipe through, but it probably is if you have many many pages of apps and folders. You can accomplish this the same way you would with any app, simply long press on a folder until it "wiggles," then drag it down to the dock (make sure there is room by dragging something off the dock if you already have four spots taken).

How to put a folder on your iPhone or iPad dock.